summaryrefslogtreecommitdiff
path: root/cpu/leon2/start.S
blob: 60d3fadef49cf30dbac7222bc1cb31c9cd4ed94c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
/* This is where the SPARC/LEON3 starts
 * Copyright (C) 2007,
 * Daniel Hellstrom, daniel@gaisler.com
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <config.h>
#include <asm/asmmacro.h>
#include <asm/winmacro.h>
#include <asm/psr.h>
#include <asm/stack.h>
#include <asm/leon.h>
#include <version.h>

/* Entry for traps which jump to a programmer-specified trap handler.  */
#define TRAPR(H)  \
	wr 	%g0, 0xfe0, %psr; \
	mov 	%g0, %tbr; \
	ba 	(H); \
	mov 	%g0, %wim;

#define TRAP(H) \
	mov	%psr, %l0; \
	ba	(H); \
	nop; nop;

#define TRAPI(ilevel) \
	mov 	ilevel, %l7; \
	mov 	%psr, %l0; \
	b 	_irq_entry; \
	mov 	%wim, %l3

/* Unexcpected trap will halt the processor by forcing it to error state */
#undef BAD_TRAP
#define BAD_TRAP ta 0; nop; nop; nop;

/* Software trap. Treat as BAD_TRAP for the time being... */
#define SOFT_TRAP TRAP(_hwerr)

#define PSR_INIT   0x1FC0	/* Disable traps, set s and ps */
#define WIM_INIT   2

/* All traps low-level code here must end with this macro. */
#define RESTORE_ALL b ret_trap_entry; clr %l6;

#define WRITE_PAUSE nop;nop;nop

WINDOWSIZE = (16 * 4)
ARGPUSHSIZE = (6 * 4)
ARGPUSH = (WINDOWSIZE + 4)
MINFRAME = (WINDOWSIZE + ARGPUSHSIZE + 4)

/* Number of register windows */
#ifndef CFG_SPARC_NWINDOWS
#error Must define number of SPARC register windows, default is 8
#endif

#define STACK_ALIGN	8
#define SA(X)	(((X)+(STACK_ALIGN-1)) & ~(STACK_ALIGN-1))

	.section ".start", "ax"
	.globl 	_start, start, _trap_table
	.globl  _irq_entry, nmi_trap
	.globl  _reset_reloc

/* at address 0
 * Hardware traps
 */
start:
_start:
_trap_table:
	TRAPR(_hardreset);		! 00 reset trap
	BAD_TRAP;			! 01 instruction_access_exception
	BAD_TRAP;			! 02 illegal_instruction
	BAD_TRAP;			! 03 priveleged_instruction
	BAD_TRAP;			! 04 fp_disabled
	TRAP(_window_overflow);		! 05 window_overflow
	TRAP(_window_underflow);	! 06 window_underflow
	BAD_TRAP;			! 07 Memory Address Not Aligned
	BAD_TRAP;			! 08 Floating Point Exception
	BAD_TRAP;			! 09 Data Miss Exception
	BAD_TRAP;			! 0a Tagged Instruction Ovrflw
	BAD_TRAP;			! 0b Watchpoint Detected
	BAD_TRAP;			! 0c
	BAD_TRAP;			! 0d
	BAD_TRAP;			! 0e
	BAD_TRAP;			! 0f
	BAD_TRAP;			! 10
	TRAPI(1);			! 11 IRQ level 1
	TRAPI(2);			! 12 IRQ level 2
	TRAPI(3);			! 13 IRQ level 3
	TRAPI(4);			! 14 IRQ level 4
	TRAPI(5);			! 15 IRQ level 5
	TRAPI(6);			! 16 IRQ level 6
	TRAPI(7);			! 17 IRQ level 7
	TRAPI(8);			! 18 IRQ level 8
	TRAPI(9);			! 19 IRQ level 9
	TRAPI(10);			! 1a IRQ level 10
	TRAPI(11);			! 1b IRQ level 11
	TRAPI(12);			! 1c IRQ level 12
	TRAPI(13);			! 1d IRQ level 13
	TRAPI(14);			! 1e IRQ level 14
	TRAP(_nmi_trap);		! 1f IRQ level 15 /
					! NMI (non maskable interrupt)
	BAD_TRAP;			! 20 r_register_access_error
	BAD_TRAP;			! 21 instruction access error
	BAD_TRAP;			! 22
	BAD_TRAP;			! 23
	BAD_TRAP;			! 24 co-processor disabled
	BAD_TRAP;			! 25 uniplemented FLUSH
	BAD_TRAP;			! 26
	BAD_TRAP;			! 27
	BAD_TRAP;			! 28 co-processor exception
	BAD_TRAP;			! 29 data access error
	BAD_TRAP;			! 2a division by zero
	BAD_TRAP;			! 2b data store error
	BAD_TRAP;			! 2c data access MMU miss
	BAD_TRAP;			! 2d
	BAD_TRAP;			! 2e
	BAD_TRAP;			! 2f
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 30-33
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 34-37
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 38-3b
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 3c-3f
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 40-43
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 44-47
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 48-4b
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 4c-4f
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 50-53
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 54-57
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 58-5b
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 5c-5f

	/* implementaion dependent */
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 60-63
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 64-67
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 68-6b
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 6c-6f
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 70-73
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 74-77
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 78-7b
	BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 7c-7f

	/* Software traps, not handled */
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 80-83
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 84-87
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 88-8b
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 8c-8f
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 90-93
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 94-97
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 98-9b
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! 9c-9f
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! a0-a3
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! a4-a7
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! a8-ab
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! ac-af
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! b0-b3
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! b4-b7
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! b8-bb
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! bc-bf
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! c0-c3
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! c4-c7
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! c8-cb
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! cc-cf
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! d0-d3
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! d4-d7
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! d8-db
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! dc-df
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! e0-e3
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! e4-e7
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! e8-eb
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! ec-ef
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! f0-f3
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! f4-f7
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! f8-fb
	SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP;	! fc-ff
/*
 * Version string
 */

	.data
	.globl	version_string
version_string:
	.ascii U_BOOT_VERSION
	.ascii " (", __DATE__, " - ", __TIME__, ")"
	.ascii CONFIG_IDENT_STRING, "\0"

	.section	".text"
	.align 4

_hardreset:
1000:
	flush
	nop
	nop
	nop

	/* Init Cache */
	set     (LEON2_PREGS+LEON_REG_CACHECTRL_OFFSET), %g1
	set     0x0081000f, %g2
	st      %g2, [%g1]

	mov	%g0, %y
	clr	%g1
	clr	%g2
	clr	%g3
	clr	%g4
	clr	%g5
	clr	%g6
	clr	%g7

	mov	%asr17, %g3
	and	%g3, 0x1f, %g3
clear_window:
	mov	%g0, %l0
	mov	%g0, %l1
	mov	%g0, %l2
	mov	%g0, %l3
	mov	%g0, %l4
	mov	%g0, %l5
	mov	%g0, %l6
	mov	%g0, %l7
	mov	%g0, %o0
	mov	%g0, %o1
	mov	%g0, %o2
	mov	%g0, %o3
	mov	%g0, %o4
	mov	%g0, %o5
	mov	%g0, %o6
	mov	%g0, %o7
	subcc	%g3, 1, %g3
	bge	clear_window
	save

leon2_init:
	/* LEON2 Register Base in g1 */
	set	LEON2_PREGS, %g1

leon2_init_cache:
	/* Set Cache control register */
	set	0x1000f, %g2
	st	%g2, [%g1 + 0x14]

leon2_init_clear:

	/* Clear LEON2 registers */
	st	%g0, [%g1 + LEON2_ECTRL]
	st	%g0, [%g1 + LEON2_IMASK]
	st	%g0, [%g1 + LEON2_IPEND]
	st	%g0, [%g1 + LEON2_IFORCE]
	st	%g0, [%g1 + LEON2_ICLEAR]
	st	%g0, [%g1 + LEON2_IOREG]
	st	%g0, [%g1 + LEON2_IODIR]
	st	%g0, [%g1 + LEON2_IOICONF]
	st	%g0, [%g1 + LEON2_UCTRL0]
	st	%g0, [%g1 + LEON2_UCTRL1]

leon2_init_ioport:
	/* I/O port initialization */
	set	0xaa00, %g2
	st	%g2, [%g1 + LEON2_IOREG]

leon2_init_mctrl:

	/* memory config register 1 */
	set	CFG_GRLIB_MEMCFG1, %g2
	ld	[%g1], %g3		!
	and	%g3, 0x300, %g3
	or	%g2, %g3, %g2
	st	%g2, [%g1 + LEON2_MCFG1]
	set	CFG_GRLIB_MEMCFG2, %g2		! Load memory config register 2
#if !( defined(TSIM) || !defined(BZIMAGE))
	st	%g2, [%g1 + LEON2_MCFG2]	! only for prom version, else done by "dumon -i"
#endif
	set	CFG_GRLIB_MEMCFG3, %g2		! Init FT register
	st	%g2, [%g1 + LEON2_ECTRL]
	ld	[%g1 + LEON2_ECTRL], %g2
	srl	%g2, 30, %g2
	andcc	%g2, 3, %g6
	bne,a	leon2_init_wim
	mov	%g0, %asr16		! clear err_reg

leon2_init_wim:
	set	WIM_INIT, %g3
	mov	%g3, %wim

leon2_init_psr:
	set	0x1000, %g3
	mov	%psr, %g2
	wr	%g2, %g3, %psr
	nop
	nop
	nop

leon2_init_stackp:
	set	CFG_INIT_SP_OFFSET, %fp
	andn	%fp, 0x0f, %fp
	sub	%fp, 64, %sp

cpu_init_unreloc:
	call	cpu_init_f
	nop

/* un relocated start address of monitor */
#define TEXT_START _text

/* un relocated end address of monitor */
#define DATA_END __init_end

reloc:
	set	TEXT_START,%g2
	set	DATA_END,%g3
	set	CFG_RELOC_MONITOR_BASE,%g4
reloc_loop:
	ldd	[%g2],%l0
	ldd	[%g2+8],%l2
	std	%l0,[%g4]
	std	%l2,[%g4+8]
	inc	16,%g2
	subcc	%g3,%g2,%g0
	bne	reloc_loop
	inc	16,%g4

	clr	%l0
	clr	%l1
	clr	%l2
	clr	%l3
	clr	%g2

/* register g4 contain address to start
 * This means that BSS must be directly after data and code segments
 *
 * g3 is length of bss = (__bss_end-__bss_start)
 *
 */

clr_bss:
/* clear bss area (the relocated) */
	set	__bss_start,%g2
	set	__bss_end,%g3
	sub	%g3,%g2,%g3
	add	%g3,%g4,%g3
	clr	%g1	/* std %g0 uses g0 and g1 */
/* clearing 16byte a time ==> linker script need to align to 16 byte offset */
clr_bss_16:
	std	%g0,[%g4]
	std	%g0,[%g4+8]
	inc	16,%g4
	cmp	%g3,%g4
	bne	clr_bss_16
	nop

/* add offsets to GOT table */
fixup_got:
	set	__got_start,%g4
	set	__got_end,%g3
/*
 * new got offset = (old GOT-PTR (read with ld) -
 *   CFG_RELOC_MONITOR_BASE(from define) ) +
 *   Destination Address (from define)
 */
	set	CFG_RELOC_MONITOR_BASE,%g2
	set	TEXT_START, %g1
	add	%g4,%g2,%g4
	sub	%g4,%g1,%g4
	add	%g3,%g2,%g3
	sub	%g3,%g1,%g3
	sub	%g2,%g1,%g2	! prepare register with (new base address) -
				!  (old base address)
got_loop:
	ld	[%g4],%l0	! load old GOT-PTR
	add	%l0,%g2,%l0	! increase with (new base address) -
				!  (old base)
	st	%l0,[%g4]
	inc	4,%g4
	cmp	%g3,%g4
	bne	got_loop
	nop

prom_relocate:
	set	__prom_start, %g2
	set	__prom_end, %g3
	set	CFG_PROM_OFFSET, %g4

prom_relocate_loop:
	ldd	[%g2],%l0
	ldd	[%g2+8],%l2
	std	%l0,[%g4]
	std	%l2,[%g4+8]
	inc	16,%g2
	subcc	%g3,%g2,%g0
	bne	prom_relocate_loop
	inc	16,%g4

/* Trap table has been moved, lets tell CPU about
 * the new trap table address
 */

	set	CFG_RELOC_MONITOR_BASE, %g2
	wr	%g0, %g2, %tbr

/*	call	relocate*/
	nop
/* Call relocated init functions */
jump:
	set	cpu_init_f2,%o1
	set	CFG_RELOC_MONITOR_BASE,%o2
	add	%o1,%o2,%o1
	sub	%o1,%g1,%o1
	call	%o1
	clr	%o0

	set	board_init_f,%o1
	set	CFG_RELOC_MONITOR_BASE,%o2
	add	%o1,%o2,%o1
	sub	%o1,%g1,%o1
	call	%o1
	clr	%o0

dead:	ta 0				! if call returns...
	nop

/* Interrupt handler caller,
 * reg L7: interrupt number
 * reg L0: psr after interrupt
 * reg L1: PC
 * reg L2: next PC
 * reg L3: wim
 */
_irq_entry:
	SAVE_ALL

	or	%l0, PSR_PIL, %g2
	wr	%g2, 0x0, %psr
	WRITE_PAUSE
	wr	%g2, PSR_ET, %psr
	WRITE_PAUSE
	mov	%l7, %o0		! irq level
	set	handler_irq, %o1
	set	(CFG_RELOC_MONITOR_BASE-TEXT_BASE), %o2
	add	%o1, %o2, %o1
	call	%o1
	add	%sp, SF_REGS_SZ, %o1	! pt_regs ptr
	or	%l0, PSR_PIL, %g2	! restore PIL after handler_irq
	wr	%g2, PSR_ET, %psr	! keep ET up
	WRITE_PAUSE

	RESTORE_ALL

!Window overflow trap handler.
	.global _window_overflow

_window_overflow:

	mov	%wim, %l3		! Calculate next WIM
	mov	%g1, %l7
	srl	%l3, 1, %g1
	sll	%l3, (CFG_SPARC_NWINDOWS-1) , %l4
	or	%l4, %g1, %g1

	save				! Get into window to be saved.
	mov	%g1, %wim
	nop;
	nop;
	nop
	st	%l0, [%sp + 0];
	st	%l1, [%sp + 4];
	st	%l2, [%sp + 8];
	st	%l3, [%sp + 12];
	st	%l4, [%sp + 16];
	st	%l5, [%sp + 20];
	st	%l6, [%sp + 24];
	st	%l7, [%sp + 28];
	st	%i0, [%sp + 32];
	st	%i1, [%sp + 36];
	st	%i2, [%sp + 40];
	st	%i3, [%sp + 44];
	st	%i4, [%sp + 48];
	st	%i5, [%sp + 52];
	st	%i6, [%sp + 56];
	st	%i7, [%sp + 60];
	restore				! Go back to trap window.
	mov	%l7, %g1
	jmp	%l1			! Re-execute save.
	rett	%l2

/* Window underflow trap handler.  */

	.global  _window_underflow

_window_underflow:

	mov  %wim, %l3			! Calculate next WIM
	sll  %l3, 1, %l4
	srl  %l3, (CFG_SPARC_NWINDOWS-1), %l5
	or   %l5, %l4, %l5
	mov  %l5, %wim
	nop; nop; nop
	restore				! Two restores to get into the
	restore				! window to restore
	ld	[%sp + 0], %l0; 	! Restore window from the stack
	ld	[%sp + 4], %l1;
	ld	[%sp + 8], %l2;
	ld	[%sp + 12], %l3;
	ld	[%sp + 16], %l4;
	ld	[%sp + 20], %l5;
	ld	[%sp + 24], %l6;
	ld	[%sp + 28], %l7;
	ld	[%sp + 32], %i0;
	ld	[%sp + 36], %i1;
	ld	[%sp + 40], %i2;
	ld	[%sp + 44], %i3;
	ld	[%sp + 48], %i4;
	ld	[%sp + 52], %i5;
	ld	[%sp + 56], %i6;
	ld	[%sp + 60], %i7;
	save				! Get back to the trap window.
	save
	jmp	%l1			! Re-execute restore.
	rett	%l2

	retl

_nmi_trap:
	nop
	jmp %l1
	rett %l2

_hwerr:
	ta 0
	nop
	nop
	b _hwerr 			! loop infinite
	nop

/* Registers to not touch at all. */
#define t_psr      l0 /* Set by caller */
#define t_pc       l1 /* Set by caller */
#define t_npc      l2 /* Set by caller */
#define t_wim      l3 /* Set by caller */
#define t_twinmask l4 /* Set at beginning of this entry routine. */
#define t_kstack   l5 /* Set right before pt_regs frame is built */
#define t_retpc    l6 /* If you change this, change winmacro.h header file */
#define t_systable l7 /* Never touch this, could be the syscall table ptr. */
#define curptr     g6 /* Set after pt_regs frame is built */

trap_setup:
/* build a pt_regs trap frame. */
	sub	%fp, (SF_REGS_SZ + PT_REGS_SZ), %t_kstack
	PT_STORE_ALL(t_kstack, t_psr, t_pc, t_npc, g2)

	/* See if we are in the trap window. */
	mov	1, %t_twinmask
	sll	%t_twinmask, %t_psr, %t_twinmask ! t_twinmask = (1 << psr)
	andcc	%t_twinmask, %t_wim, %g0
	beq	1f		! in trap window, clean up
	nop

	/*-------------------------------------------------
	 * Spill , adjust %wim and go.
	 */
	srl	%t_wim, 0x1, %g2		! begin computation of new %wim

	set	(CFG_SPARC_NWINDOWS-1), %g3	!NWINDOWS-1

	sll	%t_wim, %g3, %t_wim	! NWINDOWS-1
	or	%t_wim, %g2, %g2
	and	%g2, 0xff, %g2

	save	%g0, %g0, %g0		! get in window to be saved

	/* Set new %wim value */
	wr	%g2, 0x0, %wim

	/* Save the kernel window onto the corresponding stack. */
	RW_STORE(sp)

	restore	%g0, %g0, %g0
	/*-------------------------------------------------*/

1:
	/* Trap from kernel with a window available.
	 * Just do it...
	 */
	jmpl	%t_retpc + 0x8, %g0	! return to caller
	 mov	%t_kstack, %sp		! jump onto new stack

#define twin_tmp1 l4
#define glob_tmp  g4
#define curptr    g6
ret_trap_entry:
	wr	%t_psr, 0x0, %psr       ! enable nesting again, clear ET

	/* Will the rett land us in the invalid window? */
	mov	2, %g1
	sll	%g1, %t_psr, %g1

	set	CFG_SPARC_NWINDOWS, %g2	!NWINDOWS

	srl	%g1, %g2, %g2
	or	%g1, %g2, %g1
	rd	%wim, %g2
	andcc	%g2, %g1, %g0
	be	1f		! Nope, just return from the trap
	 sll	%g2, 0x1, %g1

	/* We have to grab a window before returning. */
	set	(CFG_SPARC_NWINDOWS-1), %g3	!NWINDOWS-1

	srl	%g2, %g3,  %g2
	or	%g1, %g2, %g1
	and	%g1, 0xff, %g1

	wr	%g1, 0x0, %wim

	/* Grrr, make sure we load from the right %sp... */
	PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1)

	restore	%g0, %g0, %g0
	RW_LOAD(sp)
	b	2f
	save	%g0, %g0, %g0

	/* Reload the entire frame in case this is from a
	 * kernel system call or whatever...
	 */
1:
	PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1)
2:
	wr	%t_psr, 0x0, %psr
	nop;
	nop;
	nop

	jmp	%t_pc
	rett	%t_npc

/* This is called from relocated C-code.
 * It resets the system by jumping to _start
 */
_reset_reloc:
	set	start, %l0
	call	%l0
	nop